1. Field of the Invention
This invention relates to control systems for radio-controlled aircraft. More specifically, this invention relates to methods and systems for modifying the flight path of a radio-controlled aircraft.
2. Description of the Related Art
The sport of flying radio-controlled aircraft has increased in popularity over the past several years. Many hobbyists spend a tremendous amount of time building and flying these radio-controlled aircraft. As is known, these aircraft are flown by a pilot that sends control signals from a transmitter to a receiver in the aircraft.
A remote controlled airplane changes direction by movement around one or more of its three axes of rotation: lateral axis, vertical axis, and longitudinal axis. These axes are imaginary lines that run perpendicularly to each other through the exact weight center of the airplane. The airplane's rotation around them is termed pitch, roll, and yaw. The pilot guides the airplane by sending control signals to servos within the airplane that change the pitch, roll, and yaw by moving the elevators, ailerons, and rudder of the airplane.
Conventional remote controlled aircraft use radio frequency signals that are sent from the pilot's transmitter to a receiver in the airplane, which in turn generate a sequence of frequency modulated signals. Each control surface in the airplane is moved by a servo that receives these frequency modulated signals. By, for example, increasing the frequency of the signal that controls the elevator servo, the pilot can cause the airplane to ascend or descend. In the same manner, changing the pulse-width of the signals to the aileron servo will cause the airplane to turn.
Unfortunately, the chance that a beginner will successfully complete their first flight can be less than 1 in 10. This fact not only deters potential hobbyists from joining the sport, but also adds to the cost of taking up this sport since so many aircraft are destroyed during the learning stages.
One reason that so many aircraft are destroyed during the learning stage of flying remote-controlled aircraft is that no inexpensive and convenient system exists for assisting a novice pilot to maneuver the plane or recover from unstable flight situations. Some systems do exist for pilotless military aircraft, such as one described in U.S. Pat. No. 4,964,598 ('598) to Berejik et al. The system described in the '598 patent relies on feedback signals from gyroscopes in the airplane to control the bank-angle and actual rate of climb of the aircraft. While such a system might be appropriate for military drones, such a system is complex and would not provide a cost effective solution for radio-controlled airplane hobbyists.
What is needed in the art is a simple and inexpensive system that can be incorporated into radio-controlled aircraft systems in order to give novice pilots the ability to fly radio controlled aircraft without risking a crash. The present invention fulfills such a need.